Web-based medical records, self-management, and social support benefit adults with HIV, diabetes, arthritis, and other conditions, but less data exist for pediatric patients. The aims of this project are: A) to evaluate, by means of laboratory-based qualitative and quantitative methods, the usability of an electronic patient portal interface; B) to evaluate the feasibility, in specialty pediatrics practice, of patient portals as measured by: 1) the proportion of eligible population who enroll in the portals; 2) retention of users over 3- and 6-month periods; 3) characteristics of patients/families who enroll in and use the portals vs. those who do not; and 4) parent and health care provider reports of the acceptability, accuracy, and usefulness of the portal; C) to generate preliminary data, hypotheses, and methods for a future R01 to determine the effects of patient portals on 1) communication between parents and providers; 2) the ability of parents to manage their child's illness at home; and 3) hassles associated with communicating with health care providers and obtaining needed information. Portals will be implemented in three pediatric clinics: diabetes, cystic fibrosis, and juvenile arthritis. Usability will be tested with 15 subjects in a computer usability laboratory, and the interfaces will be improved based on that testing. Portal usage logs and chronic disease registries will be used to determine the number and characterizes of patients who enroll and use the portals at 3 and 6 months post-enrollment. Telephone interviews with 140 users and web-based surveys with 70 health care providers will determine acceptability and perceived usefulness of the portals. Qualitative analysis of interviews with 30 portals users will explain the range of use of the portals and how parents use portals to manage their child's illness.